1. Field of the Invention
The present invention relates to a sinker mechanism disposed at the front end of a needle bed of a flat knitting machine, provided with at least a pair of needle beds, on which a plurality of knitting needles are slidably mounted in parallel, and which are disposed oppositely in front and rear positions.
2. Description of Related Art
Prior art sinker mechanisms of the type disposed at a needle bed front end of a flat knitting machine are disclosed in U.S. Pat. No. 5,134,865 and International Publication WO 89/12708, and others have been known.
In the former such prior art arrangements, an approximately arc-shaped loop forming edge is formed on a main body of the sinker at the front end portion of the needle bed, and a knitting yarn holding part is formed forwardly thereof. A guide groove for guiding the sinker to move forwardly and rearwardly and to swing with respect to an opening is formed at the needle bed front end. When the sinker swings forwardly in the guide groove, the knitting yarn holding part is caused to swing into a deep position beneath the opening gap of the needle bed, and by pushing the sinker loop of the previous course, the loop of the previous course is prevented from floating with the knitting needle when the knitting needle advances. Thus, the loop may be formed continuously.
In the latter such prior art arrangement, on the other hand, a comb bed is placed above the front end of the needle bed, and a comb jack, which is capable of swinging movement, is pivoted in a wire stretched in the longitudinal direction of the needle bed above the comb bed. The comb jack comprises a lever for adjusting the extent of swinging movement by a cam provided in a carriage in a rear part, and an elastic leg for thrusting the comb jack in the stitch pushing direction. At a front end portion of the comb jack is formed a hole so that the comb jack can swing, with the wire stretched in the longitudinal direction of the comb bed being inserted. The comb jack swings, resisting the force of the elastic leg from pushing the stitch to a deep position, by the activation of the cam provided in the carriage, and is designed to apply a tension to the former loop, depending on the length of the stitch.
However, in U.S. Pat. No. 5,134,865, since knitting is performed in a state in which the gap between the sinker and the guide groove for guiding the swinging motion of the sinker is exposed on the needle bed, in a case of a fine gauge knitting machine with a small needle pitch, in a case of pulling the knitting needle largely with the sinker pushed into a deep position, or in a case of knitting a pattern in which the tension of the knitting yarn applied between the knitting needle and sinker is intensified, the knitting yarn may fall into and be broken in the gap between the sinker and the sinker guide groove, or other troubles might occur.
In WO 89/12708, since the wire is disposed in the longitudinal direction of a comb floor at the front end portion thereof, such problem does not occur. However, a hole for inserting the wire must be formed in the front end portion of the comb jack, and the thickness of the knitting yarn holding part of the sinker is reduced, thus causing a weakening of the strength thereof.